It is known that a wireless communication terminal communicating with a base station measures the quality of communication (Received Signal/Strength Indicator, Signal-to-Interference Ratio (SIR) value, error rate, or the like) with the base station by using an idle slot and performs handoff to another base station on the basis of the measurement result.
In order to perform the handoff, it is necessary to exchange several messages so that the wireless communication terminal can perform processing, such as registration of the terminal in a new base station, after the handoff.    Patent Document 1: JP-B-H5-73297
Particularly, in handoff (idle handoff) to be performed while the wireless communication terminal is an idle state condition, when the quality of communication with another base station has become superior to that of the base station with which the wireless communication terminal is currently in an idle state condition, the wireless communication terminal determines that the idle handoff is necessary and performs the idle handoff to the another base station which provides superior communication quality.
At this time, for instance, the communication qualities of the two base stations contend with each other, and when the relative rankings of the two communication qualities frequently reverse within a short period of time, the idle handoff arises frequently.
This state is shown in FIG. 4.
Even when the communication quality of the base station (A) is sufficiently superior to that of another base station (B), the communication quality of the base station (B) becomes superior to that of the base station (A) as a result of the communication quality of the base station (A) having been considerably deteriorated during measurement for reasons of instantaneous disconnection of a radio wave or the like. Consequently, the idle handoff arises. However, the communication quality of the base station (A) recovers immediately, whereupon the idle handoff again arises.
This state is shown in FIG. 5.